31020123021 has 4 divisors (see below), whose sum is σ = 41360164032. Its totient is φ = 20680082012.

The previous prime is 31020122971. The next prime is 31020123041. The reversal of 31020123021 is 12032102013.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31020123021 - 2¹⁰ = 31020121997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31020123041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5170020501 + ... + 5170020506.

It is an arithmetic number, because the mean of its divisors is an integer number (10340041008).

Almost surely, 2^31020123021 is an apocalyptic number.

It is an amenable number.

31020123021 is a deficient number, since it is larger than the sum of its proper divisors (10340041011).

31020123021 is a wasteful number, since it uses less digits than its factorization.

31020123021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10340041010.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31020123021 its reverse (12032102013), we get a palindrome (43052225034).

The spelling of 31020123021 in words is "thirty-one billion, twenty million, one hundred twenty-three thousand, twenty-one".